Detentions - big deal or not?

Most teachers are not a fan of detentions (as they eat into our time for lunch or planning etc after school)
Teachers normally only set them for reasonably serious things (ie continually talking not whispering to a friend once) If your child got more than 1 in a term then they need a stern talking to and if the detentions are for organisation they need to be helped to create a plan of action to be more organised.

That's a bit of a sweeping 'boy' generalisation, there, admission. Certainly, ime, girls are equally likely as boys to be in trouble for talking in class, if not more so; and as for not being dressed properly, I really do think girls are, on the whole, more bothered about breaking those rules than boys. Maybe forgetting things is more common for boys...
I would be upset if ds got one detention at all. They do get second chances for forgetting things, etc at his school. And at the school I work in a detention is very serious and not very common. (As in the behaviour is very good; not that they don't pick up on it!)

As a son it is almost a guarantee that they will get some detentions, lateness, forgetting things, not being properly dressed, talking in class and general messing around are all part of a teenager sons make up as far as I am concerned.
However if it happening quite often then that is then room for some concern and a concerted effort required to get them to rise about the norm.